This research project has developed several indices of injury and illness severity. The acute indices include severity measures based upon Anatomical and Physiological data. Overall, these indices have a misclassification rate of less than 10% when compared to mortality. The results of the study to date clearly indicate that the indices can be used to evaluate the impact of emergency medical services systems. The indices can be used to control for differences in case mix between systems and thus compare different system configurations and the impact upon patient mortality. The non-acute indices are used to characterize and quantify organ system dysfunction. The current work is aimed at honing these indices and developing a multi-index descriptor of patient status using elements of the various organ specific indices. Initial results of the Joint Respiratory-Renal Index shows significant improvement over the predictive power of either index alone.